Apparatus and method for incinerating rubbish and cleaning the smoke of incineration

ABSTRACT

This specification discloses apparatus for carrying out a method of incinerating rubbish and cleaning the resultant smoke. The apparatus comprises essentially a fire pit, a plenum where smoke is collected, a filter, an after burner, an electrostatic precipitating chamber, an alkaline water wash, a plain water wash, a filter, and a motor driven exhaust fan which passes clean gas to a stack.

United States Patent Cahill, Jr. June 13, 1972 APPARATUS AND METHOD FOR[56] References Cited 21 25 2? AND UNITED STATES PATENTS O FINCINERATION 2,746,563 5/1956 Harlow ..23/2 C 3,258,897 7/1966 Mayer etal.. .....55/l52 [72] Inventor: William Francis Cahill, Jr., 8 Danecroft3522900 7/1970 Kinney Avenue, Greenville R I 02828 3,572,264 5/1971Mercer.... ...l lO/l l9 3,601,069 8/1971 Mancuso ..1 10/8 C [22] Filed:Aug. 25, 1970 21 Appl 66,682 Primary Examiner-Bernard NozickAtt0rneyWi11iam Frederick Werner [52] US. Cl. ..55/7, 23/2 C, 23/277 C,[57] ABSTRACT 55/94, 55/97, 55/126, 55/259, 110/8 A, 110/18 R, I

0/119 This specification discloses apparatus for carrying out a [51]lnt.C1 ..B01d /00 method of incinerating rubbish and cleaning theresultant 58 Field ofSearch ..55/10 2 84 94 97 124 Smke- The apparatusmmPises essentially a fire 3 /126 134 0/8 A plenum where smoke iscollected, a filter, an after burner, an 285 2 electrostaticprecipitating chamber, an alkaline water wash, a plain water wash, afilter, and a motor driven exhaust fan which passes clean gas to astack.

14 Claims, 4 Drawing Figures SOLID RESIDUE REMOVED PREClPlTATE 2oREMOVED F 2y, i l E E P t WAT T i\ T|c AFTER [E] FIRE STACK FAN g WASHER WQ SIX STATIC BURNER R PIT PHEUPHAI PRECIPiTATE REMOVED SOLlD RESIDUEREMOVED PATENTEDJuu 13 I972 SHEET 10F 4 M39 mum 030m INVENTOR WILLIAMFRANCIS CAHILL, JR.

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INVENTOR R J L H A C S C m R F M m L m W ATTORNEY PATENTEDJun 13 I972SHEET 30F 4 INVENTOR WILLlAM FRANCIS CAHILL, JR.

ATTORNEY APPARATUS AND METHOD FOR INCINERATING RUBBISH AND CLEANINGTI-IE SMOKE OF INCINERATION The present invention relates to theincineration of trashes, rubbish, and other forms of combustible wasteand is concerned primarily with a novel method and apparatus forcleaning the smoke generated by the combustion of such materials wherebyit is exhausted into the atmosphere as clean gas.

BACKGROUND OF THE INVENTION At the present time the public is aroused tothe dangers of pollution. Perhaps the most important aspect of thisperil is the pollution of the atmosphere around large cities. Anotherproblem is the disposal of all forms of waste. Many types of wastecontain some materials which are susceptible of being consumed bycombustion and converted into ash. Thus some waste often contain glassand metal which may be reclaimed for future use rather than beingdeposited in a dump.

A classic example of waste of this character is an automobile which hasbeen wrecked or junked. The upholstery, tires, and other combustiblesmay be incinerated to remove them from the metal which may be reclaimedas scrap and the glass which can be recycled to fulfill a usefulpurpose.

The disposition and reclaiming of all forms of waste, such as municipaltrash and rubbish, industrial waste, and the like by a method whichincludes incineration, immediately creates the problem of polluting theair by the smoke of incineration. While those working in this field haveattempted to clean this smoke, it is believed the results so farachieved are not satisfactory to the degree required.

OBJECTS OF THE INVENTION With the foregoing conditions in mind, theinvention has in view the following objects.

I. To provide a method of and apparatus for incinerating all forms ofwaste to reclaim incombustible components thereof and convert thecombustible components to ash and smoke, and clean the smoke to exhaustit to the air as clean gas.

2. To provide, in a method and apparatus of the type noted, a fire pitwhich receives the waste and which has associated therewith a plenum orsmoke collecting chamber.

3. To provide, in apparatus of the character aforesaid, a fire pit whichis adapted for installation at least partially underground together withchutes for charging waste thereinto.

4. To provide, in apparatus of the kind described, a plurality of smoketreatment chambers, arranged in series and connecting the plenum to astack.

5. To provide, in apparatus of the character noted, smoke treatmentchambers that are constructed as individual modules which may beconstructed off site and transported to the area of the fire pit wherethey are installed.

6. To include, in a method of the type described, the step of monitoringthe treated smoke just before it enters the stack.

Various other more detailed objects and advantages of the invention suchas arise in connection with carrying out the SUMMARY OF THE INVENTIONThe foregoing objects are achieved by providing a fire pit which ispreferably installed underground and which has associated therewithchutes for charging the pit with waste. The fire pit is covered and onone side of the roof is a plenum in which smoke is collected. Adjacentto the plenum is a filter assembly and then an after burner chamber.Following the latter is an electrostatic precipitator chamber togetherwith means to remove the precipitate. Next in line is an alkaline waterwash followed by a plain water wash. The treated smoke is then drawnthrough a filter assembly and passed to a stack. A monitor is includedin the chamber in which this last filter is located.

For a full and more complete understanding of the invention, referencemay be had to the following description and accompanying drawingswherein:

FIG. 1 is a flow sheet which illustrates diagrammatically the method ofthe subject invention;

FIG. 2 is a perspective, largely diagrammatic of an incineratorinstallation in which the method may be conducted;

FIG. 3 is a view in end elevation of the fire pit; and,

FIG. 4 is a longitudinal vertical section through the incinerator andsmoke treating apparatus being taken about on the plane of line 44 ofFIG. 2.

Referring now to the drawings wherein like reference characters denotecorresponding parts and first more particularly to FIG. I, the methodwill be described.

All forms of waste, both municipal and industrial are charged into afire pit 10. All combustible components of the waste is consumed byburning. This combustion may be facilitated by a forced air draft andthe injection of oil.

Ash and other solid residues are removed from fire pit 10 from time totime as represented by arrows 11. Smoke is collected from fire pit 10 ina plenum 12. This is accomplished by a draft generated by a motor drivenfan as will be later described. This draft may be in the nature of30,000 cubic feet per minute.

The smoke now passes through a filter assembly 13 which may comprise twocoarse filter which remove large particles from the smoke. The filteredsmoke now passes to an after burner chamber 14 in which it is subjectedto a temperature on the order of 6,000" F. created by an arc flame.Entrained particles and gases are burned by this high temperature.

From the after burner the smoke passes to an electrostatic precipitatingchamber 15 in which an electrostatic precipitator operates at apotential of 140,000 volts. This causes particles to be picked up andremoved to the side of the chamber from which they are periodicallyremoved by mechanical brushes or manually.

The smoke now is subjected to an alkaline water wash represented at 16.This wash neutralizes any acid fumes and also collects particles whichmay still be entrained in the smoke. The pH of the wash is controlled byan electrometric pH meter on the outside of the chamber.

A chamber 17 which is a duplicate of chamber 16 houses a plain waterwash. Clear water used at station 17 picks up particles still remainingin the smoke. A second filter assembly is shown at 18 and includes bothmechanical and chemical filters. A continuous air testing monitor 19 islocated in the chamber housing filter assembly 18. A motor driven fan isrepresented at 20 and is effective to create the draft that draws thesmoke from fire pit 10 through the various stages of the method andpasses it to a stack 21 as clean gas which may be exhausted to theatmosphere without danger of pollution.

Referring now to FIGS. 2 and 3, the construction of the free pit 10 willbe described. The construction illustrated is particularly adapted forunderground installation which is desirable when it is considered thatmany forms of waste often include explosives. By having the fire pitmainly underground, the danger of explosives is minimized.

Fire pit 10 includes a rear wall 22 on the exterior of which are mountedoil tanks 23. It is also provided with a clean out door 24 which may beavailed of when it is desired to charge the fire pit with a large objectsuch as a wrecked automobile. Lines 25 extend from oil tanks 23 to theinterior of pit 10 where oil is injected into the burning mass of waste.Above oil tanks 23 are fire doors 26. Extending across rear wall 22 justbelow its upper edge are three cooling doors 27 which may be selectivelyopened as occasion demands.

Side walls of pit 10 are shown at 28 in FIG. 3. Each wall 28 is formedwith a charging opening 29 and communicating with each opening 29 is achute 30. Each of the latter is provided with a vertically reciprocatingsafety gate 31.

A roof 32 covers fire pit l0 and mounted thereon is structure 33constituting plenum 12 of FIG. 1. The bottom of plenum structure 33opens onto the interior of fire pit l0.

Referring now to FIG. 4, plenum structure 33 includes an open side inwhich filter assembly 13 is mounted. Assembly 13 comprises two coarsefilters 34 which preferably are mechanical.

After burner station 14 is shown as provided by a module 35 which houseselectrodes 36 which generate arc 37.

The electrostatic precipitator at 15 is also constructed as a module 38.Suspended in the latter are a plurality of precipitators 39 whichreceive electric current at a potential of 140,000 volts.

Station 16 for the alkaline water wash is provided by a module 40.Housed in the latter are spray heads 41. An electrometric pH meter 42 ispreferably mounted on the exterior of module 40.

Module 43 is similar in structure to module 40 and houses the sprayheads which perform the plain water washing at station 17.

A module 44 houses filter assembly 18 and the fan representeddiagrammatically in FIG. 1 at 20. It is believed to be desirable thatone of the filters of assembly 18 be mechanical and the other chemical.Thus, filter 45 is a mechanical filter and filter 46 is chemical.

A motor 47 is mounted on module 44 and drives fan 20. A conduit 48connects module 44 to stack 21.

As illustrated in FIG. 2, plenum structure 33 is built as a module. Thismodule, like modules 35, 38, 40, 43 and 44 are formed with flanges 49which facilitate their assembly as illustrated in FIG. 4. Normally theassembled modules are supported by a foundation 50.

The manner in which the apparatus of FIGS. 2, 3 and 4 function isbelieved to be obvious from the description of the method as set forthabove in conjunction with FIG. 1.

While a preferred specific embodiment of the invention is hereinbeforeset forth, it is to be clearly understood that the invention is not tobe limited to the exacts steps, constructions and devices illustratedand described because various modifications of these details may beprovided in putting the invention into practice.

What is claimed is:

1. In the disposal and reclaiming of components of refuse, the methodcomprising the steps of:

a. depositing refuse including combustible and incombustible componentsin a fire pit, burning the combustible components in said fire pit,

c. removing the incombustible components from said fire pit,

d. collecting smoke generated by the burning of said combustiblecomponents in a plenum,

e. passing the smoke from said plenum through a coarse filter assemblyunder the influence ofa forced draft,

. burning particles and gases in said smoke in an after burner chamberto which the smoke is passed by said draft,

g. precipitating particles from the smoke by electrostatic precipitationin a chamber into which the smoke is delivered by said draft,

h. washing the smoke in an alkaline water wash,

i. washing the smoke in a plain water wash,

j. passing the smoke through a second filter assembly; and

k. passing the filtered smoke into a stack from which it is exhausted tothe atmosphere as clean gas.

2. The method of claim 1 together with the steps of periodicallyremoving precipitate from the chamber in which electrostaticprecipitation takes place.

3. The method of claim 1 in which the character of the smoke iscontinuously monitored before it is passed to the stack and the natureof the filters altered in accordance with information derived from themonitoring.

4. The method of claim 1 in which the after burning is carried out by anelectric are at a temperature on the order of 6,000 F.

5. The method of claim 1 in which the electrostatic precipitation iscarried out under a potential on the order of 140,000 volts.

6. In apparatus for burning and reclaiming incombustible components ofrefuse,

a. a fire pit,

b. a plenum for collecting smoke generated by combustion in said firepit,

c. a coarse filter assembly adjacent to said plenum, d. an after burnerchamber adjacent to said filter assembly and including electric aregenerating means,

a chamber adjacent to said after burner chamber and housing anelectrostatic precipitator, f. a chamber adjacent to that housing saidelectrostatic precipitator and including spray heads for alkaline water,a chamber adjacent to that housing the spray heads for alkaline waterand including spray heads for plain water, a second filter assemblyadjacent to said last mentioned chamber,

i. a fan for creating a forced draft that draws smoke into said plenumand through said chambers,

j. power means for driving said fan; and

k. a conduit for passing smoke from said second filter assembly to astack from which the cleaned smoke is exhausted to the atmosphere.

7. The apparatus of claim 6 in which the plenum and chambers areconstructed as independent modules and later assembled at the site ofthe fire pit.

8. The apparatus of claim 6 in which the fire pit includes a clean outdoor and chutes for charging refuse into said fire pit.

9. The apparatus of claim 6 in which a portion of the fire pit isinstalled underground.

10. The apparatus of claim 6 together with means for removingprecipitate from the sides of the chamber housing the electrostaticprecipitator.

11. The apparatus of claim 6 in which the coarse filter assemblycomprises two coarse filters.

12. The apparatus of claim 6 together with an electrometric pH metermounted on the chamber housing the spray heads for alkaline water.

13. The apparatus of claim 6 together with a continuously operatingmonitor mounted in the module containing the second filter assembly.

14. The apparatus of claim 6 in which the second filter assemblyincludes both mechanical and chemical filters.

2. The method of claim 1 together with the steps of periodicallyremoving precipitate from the chamber in which electrostaticprecipitation takes place.
 3. The method of claim 1 in which thecharacter of the smoke is continuously monitored before it is passed tothe stack and the nature of the filters altered in accordance withinformation derived from the monitoring.
 4. The method of claim 1 inwhich the after burning is carried out by an electric arc at atemperature on the order of 6,000* F.
 5. The method of claim 1 in whichthe electrostatic precipitation is carried out under a potential on theorder of 140,000 volts.
 6. In apparatus for burning and reclaimingincombustible components of refuse, a. a fire pit, b. a plenum forcollecting smoke generated by combustion in said fire pit, c. a coarsefilter assembly adjacent to said plenum, d. an after burner chamberadjacent to said filter assembly and including electric arc generatingmeans, e. a chamber adjacent to said after burner chamber and housing anelectrostatic precipitator, f. a chamber adjacent to that housing saidelectrostatic precipitator and including spray heads for alkaline water,g. a chamber adjacent to that housing the spray heads for alkaline waterand including spray heads for plain water, h. a second filter assemblyadjacent to said last mentioned chamber, i. a fan for creating a forceddraft that draws smoke into said plenum and through said chambers, j.power means for driving said fan; and k. a conduit for passing smokefrom said second filter assembly to a stack from which the cleaned smokeis exhausted to the atmosphere.
 7. The apparatus of claim 6 in which theplenum and chambers are constructed as independent modules and laterassembled at the site of the fire pit.
 8. The apparatus of claim 6 inwhich the fire pit includes a clean out door and chutes for chargingrefuse into said fire pit.
 9. The apparatus of claim 6 in which aportion of the fire pit is installed underground.
 10. The apparatus ofclaim 6 together with means for removing precipitate from the sides ofthe chamber housing the electrostatic precipitator.
 11. The apparatus ofclaim 6 in which the coarse filter assembly comprises two coarsefilters.
 12. The apparatus of claim 6 together with an electrometric pHmeter mounted on the chamber housing the spray heads for alkaline water.13. The apparatus of claim 6 together with a continuously operatingmonitor mounted in the module containing the second filter assembly. 14.The apparatus of claim 6 in which the second filter assembly includesboth mechanical and chemical filters.